net: bridge: vlan: add new rtm message support

Add initial RTM_NEWVLAN support which can only create vlans, operating
similar to the current br_afspec(). We will use it later to also change
per-vlan options. Old-style (flag-based) vlan ranges are not allowed
when using RTM messages, we will introduce vlan ranges later via a new
nested attribute which would allow us to have all the information about a
range encapsulated into a single nl attribute.
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/bridge/br_netlink.c

@@ -561,7 +561,7 @@ static int br_vlan_info(struct net_bridge *br, struct net_bridge_port *p,
 	return err;
 }
 
-static int br_process_vlan_info(struct net_bridge *br,
+int br_process_vlan_info(struct net_bridge *br,
 			 struct net_bridge_port *p, int cmd,
 			 struct bridge_vlan_info *vinfo_curr,
 			 struct bridge_vlan_info **vinfo_last,

net/bridge/br_private.h

@@ -1237,6 +1237,12 @@ int br_setlink(struct net_device *dev, struct nlmsghdr *nlmsg, u16 flags,
 int br_dellink(struct net_device *dev, struct nlmsghdr *nlmsg, u16 flags);
 int br_getlink(struct sk_buff *skb, u32 pid, u32 seq, struct net_device *dev,
 	       u32 filter_mask, int nlflags);
+int br_process_vlan_info(struct net_bridge *br,
+			 struct net_bridge_port *p, int cmd,
+			 struct bridge_vlan_info *vinfo_curr,
+			 struct bridge_vlan_info **vinfo_last,
+			 bool *changed,
+			 struct netlink_ext_ack *extack);
 
 #ifdef CONFIG_SYSFS
 /* br_sysfs_if.c */

net/bridge/br_vlan.c

@@ -1643,13 +1643,124 @@ static int br_vlan_rtm_dump(struct sk_buff *skb, struct netlink_callback *cb)
 	return err;
 }
 
+static const struct nla_policy br_vlan_db_policy[BRIDGE_VLANDB_ENTRY_MAX + 1] = {
+	[BRIDGE_VLANDB_ENTRY_INFO]	= { .type = NLA_EXACT_LEN,
+					    .len = sizeof(struct bridge_vlan_info) },
+};
+
+static int br_vlan_rtm_process_one(struct net_device *dev,
+				   const struct nlattr *attr,
+				   int cmd, struct netlink_ext_ack *extack)
+{
+	struct bridge_vlan_info *vinfo, *vinfo_last = NULL;
+	struct nlattr *tb[BRIDGE_VLANDB_ENTRY_MAX + 1];
+	struct net_bridge_vlan_group *vg;
+	struct net_bridge_port *p = NULL;
+	int err = 0, cmdmap = 0;
+	struct net_bridge *br;
+	bool changed = false;
+
+	if (netif_is_bridge_master(dev)) {
+		br = netdev_priv(dev);
+		vg = br_vlan_group(br);
+	} else {
+		p = br_port_get_rtnl(dev);
+		if (WARN_ON(!p))
+			return -ENODEV;
+		br = p->br;
+		vg = nbp_vlan_group(p);
+	}
+
+	if (WARN_ON(!vg))
+		return -ENODEV;
+
+	err = nla_parse_nested(tb, BRIDGE_VLANDB_ENTRY_MAX, attr,
+			       br_vlan_db_policy, extack);
+	if (err)
+		return err;
+
+	if (!tb[BRIDGE_VLANDB_ENTRY_INFO]) {
+		NL_SET_ERR_MSG_MOD(extack, "Missing vlan entry info");
+		return -EINVAL;
+	}
+
+	vinfo = nla_data(tb[BRIDGE_VLANDB_ENTRY_INFO]);
+	if (vinfo->flags & (BRIDGE_VLAN_INFO_RANGE_BEGIN |
+			    BRIDGE_VLAN_INFO_RANGE_END)) {
+		NL_SET_ERR_MSG_MOD(extack, "Old-style vlan ranges are not allowed when using RTM vlan calls");
+		return -EINVAL;
+	}
+	if (!br_vlan_valid_id(vinfo->vid, extack))
+		return -EINVAL;
+
+	switch (cmd) {
+	case RTM_NEWVLAN:
+		cmdmap = RTM_SETLINK;
+		break;
+	}
+
+	err = br_process_vlan_info(br, p, cmdmap, vinfo, &vinfo_last, &changed,
+				   extack);
+	if (changed)
+		br_ifinfo_notify(cmdmap, br, p);
+
+	return err;
+}
+
+static int br_vlan_rtm_process(struct sk_buff *skb, struct nlmsghdr *nlh,
+			       struct netlink_ext_ack *extack)
+{
+	struct net *net = sock_net(skb->sk);
+	struct br_vlan_msg *bvm;
+	struct net_device *dev;
+	struct nlattr *attr;
+	int err, vlans = 0;
+	int rem;
+
+	/* this should validate the header and check for remaining bytes */
+	err = nlmsg_parse(nlh, sizeof(*bvm), NULL, BRIDGE_VLANDB_MAX, NULL,
+			  extack);
+	if (err < 0)
+		return err;
+
+	bvm = nlmsg_data(nlh);
+	dev = __dev_get_by_index(net, bvm->ifindex);
+	if (!dev)
+		return -ENODEV;
+
+	if (!netif_is_bridge_master(dev) && !netif_is_bridge_port(dev)) {
+		NL_SET_ERR_MSG_MOD(extack, "The device is not a valid bridge or bridge port");
+		return -EINVAL;
+	}
+
+	nlmsg_for_each_attr(attr, nlh, sizeof(*bvm), rem) {
+		if (nla_type(attr) != BRIDGE_VLANDB_ENTRY)
+			continue;
+
+		vlans++;
+		err = br_vlan_rtm_process_one(dev, attr, nlh->nlmsg_type,
+					      extack);
+		if (err)
+			break;
+	}
+	if (!vlans) {
+		NL_SET_ERR_MSG_MOD(extack, "No vlans found to process");
+		err = -EINVAL;
+	}
+
+	return err;
+}
+
 void br_vlan_rtnl_init(void)
 {
 	rtnl_register_module(THIS_MODULE, PF_BRIDGE, RTM_GETVLAN, NULL,
 			     br_vlan_rtm_dump, 0);
+	rtnl_register_module(THIS_MODULE, PF_BRIDGE, RTM_NEWVLAN,
+			     br_vlan_rtm_process, NULL, 0);
 }
 
 void br_vlan_rtnl_uninit(void)
 {
 	rtnl_unregister(PF_BRIDGE, RTM_GETVLAN);
+	rtnl_unregister(PF_BRIDGE, RTM_NEWVLAN);
 }